Electrolytic cell

ABSTRACT

AN ELECTROLYTIC CELL HAVING A HEAT EXCHANGING SHELL DISPOSED THEREIN AND DIVIDING THE CELL CONTAINER INTO AN UPPER AND LOWER ELECTROLYTE CHAMBER. ELECTRODE TUBE MEANS EXTEND THROUGH SAID SHELL AND ARE IN COMMUNICATION WITH SAID ELECTROLYTE CHAMBER. ELECTRODE MEANS ARE DISPOSED IN SAID ELECTRODE TUBE MEANS IN A MANNER TO PRESERVE SAID COMMUNICATION. DOWNCOMER TUBE MEANS, INTERSPERSED AMONG SAID ELECTRODE TUBE MEANS, ALSO EXTEND THROUGH THE SHELL INTO COMMUNICATION WITH SAID ELECTROLYTE CHAMBER. BAFFLE ARRANGEMENTS IN SAID SHELL, AND ARRANGEMENTS OF SAID ELECTRODE TUBE MEANS AND SAID DOWNCOMER TUBES, IMPROVE THE EFFICIENCY OF THE CELL.   D R A W I N G

Sept. 19, 1972 MacMuLLlN ETAL 3,692,660

ELECTROLYTIC CELL Filed Sept. 25, 1970 4 2 Sheets-Sheet l GQG' 88888 150' Q Q Q Q Q Q 2 0 0 0 0 0 0 0 0 0 0 0 Q fifi A \J L INVENTORS 1 L \LRB. MAC MVULLIN I 34 40 BY I N f w v. CHIL.

/ FIG. 2 r I y wag ,4 T TORNEYS Sept. 19, 1972 B, MacMULLlN ETAI.3,692,660

ELECTROLYTIC CELL Filed Sept. 25, 1970 2 Sheets-Sheet 2 INVENTORS RB.MAC MULLIN 4 H. M. FOX

By F. N. RUEHLEN 3 WV. CHILDS y ATTORNEYS United states Patent once3,692,660 Patented Sept. 19, 1972 3,692,660 ELECTROLYTIC CELL Robert B.MacMullin, Niagara Falls, N.Y.; and Homer M. Fox, Forrest N. Ruehleu,and William V. Childs,

Bartlesville, Okla. (all Phillips Petroleum Company,

Bartlesville, Okla. 74003) Filed Sept. 25, 1970, Ser. No. 75,316 Int.Cl. B01k 3/00 US. Cl. 204-246 12 Claims ABSTRACT OF THE DISCLOSURE Anelectrolytic cell having a heat exchanging shell disposed therein anddividing the cell container into an upper and lower electrolyte chamber.Electrode tube means extend through said shell and are in communicationwith said electrolyte chamber. Electrode means are disposed in saidelectrode tube means in a manner to preserve said communication.Downcomer tube means, interspersed among said electrode tube means, alsoextend through the shell into communication with said electrolytechamber. Bafile arrangements in said shell, and arrangements of saidelectrode tube means and said downcomer tubes, improve the efficiency ofthe cell.

This invention relates to improved electrolytic cells.

Electrolytic cells comprising a heat exchanging shell disposed in thecell container are known in the art. For example, US. Pat. 3,404,083,issued Oct. 1, 1968, in the name of M. S. Kircher, relates to anelectrolytic cell of this type. In the cells described in said patent,cylindrical cathodic tubes extend vertically through the heat exchangingshell and are in communication with an upper and a lower electrolytechamber which contains a liquid electrolyte. An anode is suspended ineach of said cathodic tubes in a manner to leave an annulus between thewall of the cathodic tube and the outer wall of the anode. Interspersedamong said cathodic tubes are other open tubes, generally like saidcathodic tubes, but which do not contain an anode and are referred to asdowncomer tubes. A coolant inlet is connected to one side of said shellfor the introduction of a coolant medium. A coolant outlet means isconnected to an opposite side of said shell to provide an outlet forsaid coolant medium. In operation, heat is liberated at the anode andcreates a thermal siphon and electrolyte circulates upwardly from thelower to the upper electrolyte chamber and cools the anode. Heat isdissipated through the walls of the cathodic tubes into the coolantflowing through the heat exchanging shell.

In electrolytic cells of this type, difficulties are encountered fromnonuniform cooling of the walls of the various cathodic tubes, with sometubes being cooled more than others. This can result in nonuniformoperating temperatures of the anodes in the various cathodic tubes. Insome processes this is a serious operating problem. Overcooling the wallof a cathodic tube can cause the formation of a film of overcooledelectrolyte on said wall. Since the conductivity of the electrolytedecreases with decreasing temperature, the resistivity of the cell willbe increased and a higher voltage will be required to maintain thedesired constant current flow. This will resuit in increased powercosts. Furthermore, since electrolytic cells are normally operated atlow voltages, any increase in voltage drop is a serious matter becauseit rapidly decreases the cell efficiency. In some cases, such as wherethe electrolyte has a freezing point close to the cell operatingtemperature, crystallization of the electrolyte on the wall of thecathodic tube can occur. In aggravated cases this can lead to blockageof the annular space between the wall of the anode and the wall of thecathodic tube. Increasing the temperature of the entering coolant mediumdoes not provide an adequate solution because this results in a markeddecrease in cooling efficiency due to the decrease in the temperaturedifferential between the coolant and the electrolyte being cooled.

In some electrochemical conversion processes, such as electrochemicalfluorination, it is important and highly desirable that all theelectrodes, e.g., anodes, at which the reaction is occurring beat'essentially the same temperature. This is difiicult to accomplish,particularly in large cells containing a multiplicity of anodes. It isalso desirable that diiferences in temperature of the electrolyte in theupper and lower electrolyte chambers be as small as possible. This isalso difiicult to accomplish, particularly in large cells.

The present invention provides a solution for the above describedproblems. The present invention provides an improved heat exchangershell for cells of the type described, wherein multipath flow of coolantis obtained. Preferably, said multipath flow is also countercurrent withrespect to flow of electrolyte in the downcomer tubes. It has also beenfound that by providing arrangements of the downcomer tubes and theelectrode-containing tubes, wherein each downcomer tube is positionedgenerally at the center of a cluster of electrode-containing tubes, theCooling efliciency and general efiiciency of the cell can be furtherimproved.

Thus, according to the invention, there is provided an electrolytic cellcomprising: a container; a heat exchanging shell mounted in saidcontainer and dividing said container into an upper electrolyte chamberand a lower electrolyte chamber; a coolant inlet means connected to awall of said heat exchanging shell; a coolant outlet means connected toa wall of said heat exchanging shell at a point spaced apart from saidinlet means in a generally vertical direction; at least one baflle meansextending generally horizontally across said heat exchange shell from awall thereof and between said inlet means and said outlet means so as toprovide multiple pass flow of coolant through said shell between saidinlet means and said outlet means; at least one electrode tube meansextending in a generally vertical direction through said shell and saidbaffle means, and in communication with said upper and lower electrolytechambers; and at least one downcomer tube means extending in a generallyvertical direction through said shell and said baflle means, and incommunication with said upper and lower electrolyte chambers.

A number of advantages are obtained or realized when employing theimproved cell of the invention. By providing bafiles in the heatexchanging shell so as to induce multiple pass flow of coolant throughsaid shell, essentially the same amount of cooling with respect to allthe electrodes in the cell can be obtained. In other words, essentiallythe same amount of cooling is obtained on the electrodes which are mostremoved from the coolant inlet as is obtained on the electrodes whichare adjacent said coolant inlet. This makes possible much more uniformoperations of the multiple electrodes in the cell. Furthermore,overcooling of the walls of the electrode tubes near the coolant inletis also avoided. This eliminates danger of forming an overcooled film ofelectrolyte on the walls of the electrode tubes which causes increasedpower requirements, and also makes it possible to maintain a greatertemperature diiferential between the temperature of a coolant and thetemperature of the electrolyte to be cooled. This provides for maximumefliciency in the cooling of the electrolyte. The preferredcountercurrent flow of coolant with respect to the flow of electrolytein the cell also improves cell etliciency in that smaller downcomertubes can be employed. Thus, more electrode tubes can be employed percell. This increases overall cell efiiciency because the cell throughputis increased. Still another advantage of the invention is that theflexibility of the cell is increased. The number of differentelectrolytes which can be used in any given cell arrangement is greaterbecause the danger or risk of forming an overcooled film of electrolyte,or of freezing of any particular electrolyte on the walls of theelectrode tubes, can be eliminated.

The invention is applicable to and can be employed in cells for carryingout a Wide variety of electrochemical conversion processes using a Widevariety of electrolytes. The invention is particularly applicable tocells wherein the electrolyte being used has a freezing point relativelyclose to the desired cell operating temperatures. The essentiallyanhydrous liquid hydrogen fluoride electrolytes containing aconductivity additive, such as potassium fluoride, are examples of suchelectrolytes. Thes electrolytes are used in processes for theelectrochemical fiuorination of fluorinatable compounds. Saidconductivity additives can be present in the electrolyte in any suitablemolar ratio of additive to hydrogen fluoride ranging from about 1:45 to1:1 and having freezing points within the range of about 50 to about 200C. A presently preferred group of said electrolytes includes thosehaving a con ductivity additive to hydrogen fluoride ratio within therange of about 1:4 to about 1:2 and having freezing points within therange of about 60 to about 75 C. Since the preferred cell operatingtemperature in fluorination processes employing those electrolytes isusually within the range of about 60 to about 105 C., commonly about 80to about 100 C., it is important that the wall of the cathodic tube notbe overcooled so as to avoid the formation of an overcooled film, orcrystallization or freezing of said electrolytes, on the walls of saidcathodic tube.

FIG. 1 is an elevation view, taken partly in cross section along theline 11 of FIG. 2, of a cell structure in accordance with theirinvention.

FIG. 2 is a diagrammatic plan view of the cell illustrated in FIG. 1.

FIG. 3 is a cross-sectional view taken along the line 3-3 of FIG. 2.

FIG. 4 is a diagrammatic plan view of another cell structure inaccordance with the invention.

FIGS. 5, 6, 7, and 8 are diagrammatic illustrations of variousembodiments of a heat exchanging shell which can be employed in the cellof FIG. 1.

FIG. 9 is a diagrammatic plan view of a downcomer tube means in the heatexchanging shell of the cell of FIG. 1, showing the inclusion of fins onthe walls of said downcomer tube.

FIG. 10 is a cross section of one type of anode which can be employed inthe cells of the invention.

Referring now to the drawings, wherein like reference numerals have beenemployed to denote like elements, the invention will be more fullyexplained. In FIGS. 1, 2 and 3, there is illustrated an electrolyticcell, designated generally by the reference number 10, which comprises acontainer 12 having a heat exchanging shell 14 mounted therein. Saidcontainer and heat exchanging shell can be fabricated integrally, butpreferably are fabricated separately and the heat exchanging shell thenmounted in said container 12, as shown. Any convenient means can beemployed for mounting and/or supporting the heat exchanging shell in thecell container. For example, lugs 15 can be employed. Said heatexchanging shell 14 divides said container 12 into an upper electrolytechamber 16 and a lower electrolyte chamber 18. A coolant inlet meanscomprises a header conduit 20, and a plurality of inlet conduits 22(only one is shown) connected to a wall of said container and incommunication With a passageway 24 formed in said heat exchanging shell.A coolant outlet means comprises a header conduit 26, and a plurality ofoutlet conduits 28 (only one is shown) connected to a wall of saidcontainer and in communication with another passageway 30 formedtherein. Preferably, said coolant inlet means and said coolant outletmeans are connected to opposite walls of said heat exchanging shell, andalso spaced apart vertically, as illustrated in the drawing. However, itis within the scope of the invention for said coolant outlet means andsaid coolant inlet means to be connected to the same wall of the heatexchanging shell, as illustrated in FIGS. 5 and 6. In such instances, itis usually preferred that said coolant inlet means and said coolantoutlet means be connected to said same Wall, one above the other, i.e.spaced apart vertically. The relative vertical positions of said coolantinlet means and said coolant outlet means can be reversed from thatshown, depending upon the service of the cell. Said container 12 andheat exchanging shell 14 can be constructed of any suitable metal, suchas steel, stainless steel, or the like. It is preferred that the heatexchanging shell 14 be constructed of a metal or other material having ahigh heat conductivity.

At least one baffle means 32 extends generally horizontally across saidheat exchange shell from a wall thereof, to a point adjacent an oppositewall thereof, and between said coolant inlet means and said coolantoutlet means so as to form said passageways 24 and 30 and providemultiple pass flow of coolant within said shell between said coolantinlet means and said coolant outlet means Depending upon the size of thecell and the heat exchanging shell mounted therein, it is usuallypreferred to employ a plurality of said baffle means 32 so as to providemore flow passageways through said heat exchange shell. When said heatexchange shell 14 and said container 12 are fabricated integrally, thewall(s) of container 12 become wall(s) of said heat exchanging shell,and said bafile means 32 are connected thereto.

As here illustrated, a plurality of cathodic tube means 34 extend in agenerally vertical direction through said heat exchanging shell 14 andare in communication with said upper electrolyte chamber 16 and saidlower electrolyte chamber 18. An anode means 36 is disposed in each ofsaid cathodic tubes 34 in a manner to provide an annular space 38surrounding said anode means so as to preserve said communicationbetween the upper and lower electrolyte chambers.

A plurality of downcomer tube means 40 extend in a generally verticaldirection through said heat exchanging shell 14 and also are incommunication with said upper electrolyte chamber '16 and said lowerelectrolyte chamber 18. Said downcomer tubes 40 are open tubes and donot contain any electrode structure. If desired, the inner wall of saiddowncomer tubes 40 can be provided with internally extending fins 42, asillustrated in FIG. 9. Preferably, said cathodic tube means 34 and saiddowncomer tube means 40 are arranged in alternate rows, with respect toeach other, which rows extend across said shell and thus across saidcontainer. Still more preferably, the centers of said downcomer tubes 40in a row thereof are positioned between the centers of said cathodictubes 34 in an adjacent row thereof. See FIG. 2. In the presently mostpreferred arrangement, each one of said downcomer tubes 40 is disposedgenerally at the center of a cluster of a plurality of said cathodictubes 34. See FIG. 2 wherein a said cluster of cathodic tubes 34comprises 4 tubes arranged in a generally rectangular pattern with adowncomer tube 40 at the general center of the rectangle. While in FIGS.1, 2 and 3, the cells of the invention have been illustrated ascontaining a plurality of said cathodic tubes 34 and a plurality of saiddowncomer tubes 40', it is within the scope of the invention to providethe cell with only one cathodic tube 34 and only one downcomer tube 40.The cells of the invention have been illustrated as having a pluralityof cathodic tubes 3-4 and a plurality of downcomer tubes 40 because thisis the usually preferred arrangement in commercial installation, and isthe arrangement in which the invention finds its greatest and mostvaluable application.

In FIGS. -8 there are illustrated various arrangements of the coolantinlet means and the coolant outlet means in relation to the baflles 32which are provided to induce multiple pass flow through heat exchangingshell 14. In FIG. 5 said coolant inlet means and coolant outlet meansare both connected to the same wall of the heat exchanging shell and arepositioned one above the other. A single baffle means 32 is connected tosaid same wall of the heat exchanging shell and extends therefrombetween said inlet means and said outlet means to a point adjacent butspaced apart from the opposite Wall of sa d heat exchanging shell. Itwill be understood that said bafile means is also connected to the twoside walls of the heat exchanging shell which are not shown so as tocause multipass flow of coolant medium as indicated by the arrow in thedrawing. In FIG. 6 the coolant inlet means is positioned adjacent to andspaced apart from the top of heat exchanging shell 14, and the coolantoutlet means is positioned adjacent to and spaced apart from the bottomof said heat exchanging shell. It will be understood that, dependingupon the desired flow of the coolant medium, it is within the scope ofthe invention for said coolant inlet means and said coolant outlet meansto be reversed in position, i.e., the coolant inlet means can bepositioned adjacent the bottom of the shell and the coolant outlet meanspositioned adjacent to the top of the shell. In FIG. 6 a plurality ofsaid bafiie means 32 is provided. A first one of said baffle means isconnected to the wall of the shell above the one of said inlet means orsaid outlet means which is positioned adjacent to the bottom of theshell, and the last one of said baffle means is connected to the wall ofthe shell below the other of said inlet means orsaid outlet means whichis positioned adjacent the top of the shell. FIGS. 7 and 8 illustrateother arrangements of said bafile means 32; in FIGS. 7 and 8 it will benoted that the coolant inlet means and the coolant outlet means areconnected to opposite walls of said heat exchanging shell 14. Thearrangements illustrated in FIGS. 1, 7, and 8 represent presentlypreferred arrangements with the coolant inlet and coolant outletconnected to said opposite walls. Preferably, said inlet and outlet arepositioned vertically in a manner to provide countercurrent flow ofcoolant medium with respect to the flow of electrolyte through annularspace 38. For example, with flow of electrolyte upward through saidannular space 38 the coolant inlet 20 would be connected as shown inFIG. 1. This provides maximum efficiency in heat removal and, togetherwith the multipass cross flow of coolant and the above-described clusterarrangement of downcomer tubes and electrode tubes, provides maximumefficiency in maintaining all the electrodes in the electrode tubes atessentially the same operating temperature.

Said anode means 36 can comprise any suitable type of anode structure,depending upon the requirements of the electrolytic conversion processto be carried out in the cell 10. An enlarged cross-sectional view ofsaid anode 36 is shown in FIG. 10. As illustrated in FIGS. 1 and 10,said anode structure is a composite carbon anode structure comprising afirst or outer section of porous carbon 44 which is generallycylindrical in shape and is hollow. A second or core section of lessporous carbon, or essentially impervious carbon, 46 has the generalshape of a generally cylindrical rod and is disposed within said firstsection of carbon 44 and secured herein by any suitable means, such as afriction fit. A current collector 48, here shown to be a hollow metalconduit, such as copper, extends into said second section of carbon 46.Said current collector can be disposed in a hole drilled to fit andaccommodate the metal conduit, or said current collector can be threadedinto said second section of carbon. Said first section of carbon 44extends at the lower end thereof beyond the lower end of said secondsection of carbon 46. The bottom surface of said second section ofcarbon 46, together with the inner surfaces of said extended portion ofsaid first section of carbon 44, define a cavity 50 in the lower portionof the anode. A vaporous feedstock can be introduced from feedstockheader 52 by means of the header arrangement shown and passed throughsaid current collector 48 to cavity 50 for introduction into porouscarbon section 44 of the anode 36. Each of the current collectors 48 isconnected by means of a suitable lead 54 to the anode bus 56. The heatexchanging shell means 14 can be rendered cathodic by means of anysuitable connection thereto which is also connected to the cathode busof the electric current source. If desired, the entire cell container 12can be rendered cathodic by suitable connections thereto. In suchinstances the heat exchanging shell 14 would be connected to container12 by suitable means.

It will be noted that each of the anodes 36 is individually suspended bymeans of suspension means 60 in a cathodic tube 34 and is individuallyconnected to feedstock header 52, and the anode bus 56. Said suspensionmeans 60 can comprise any suitable suspension means. As hereillustrated, said suspension means comprises a flange member whichcovers an opening 62 in the top of container 12. Said opening is largeenough to permit the ready removal of the anode 36 from the container.Said suspension means or closure members 60 can be made of any suitablemetal, properly insulated from the container shell, or can be made ofany suitable insulating material such as Teflon or other suitableplastic material.

Referring now to FIG. 4, there is illustrated a cell structure generallysimilar to that illustrated in FIGS. 1, 2, and 3 except that thecontainer 12 is generally circular in shape. The heat exchanging means14' conforms in shape to the shape of said container 12'. As in FIGS. 1,2, and 3, a plurality of downcomer tubes 40 and a plurality of cathodictube means 34 are arranged as described above in connection with saidFIGS. 1, 2, and 3. While not shown in FIG. 4, it will be understood thatthe cell of FIG. 4 can be provided with suitable baffle means 32 andinlet conduit means and outlet conduit means arranged as described abovein connection with FIGS. 1, 2, 3, and 5-8, so as to provide multipassflow of coolant through the cell.

In the operation of the cell structure illustrated in the drawings, forexample, in the fluorination of a fiuorinatable feedstock such asethylene dichloride, an essentially anhydrous KF-ZHF electrolyte isintroduced into the cell. The level of said electrolyte 64 is preferablymaintained slightly above the tops of the anode structures 36. Theethylene dichloride feedstock in vapor form is passed via conduct 52through hollow current collector 48 and introduced into cavity 50. Saidfeedstock then enters the porous carbon section 44 of anode 36, travelsupwardly therethrough, and within the pores of said anode is at leastpartially fiuorinated. Products of the reaction and unreacted feedstockexit from the top of the porous section of the anode and are withdrawnfrom the cell via conduit 66 and passed to any suitable separation meansfor the recovery of the products. If desired, the unconverted feedstockcan be recycled to the call by means of a recycle line not shown. Duringthe cell operation, the heat liberated at anodes 36 creates a thermalsiphon in the cathodic tube 34, causing electrolyte to circulate fromlower electrolyte chamber 18 up through annular space 38 and into upperelectrolyte chamber 16, as shown by the arrows in the drawing. Hydrogenliberated from the walls of cathodic tubes 34 aid this circulation by agas lift effect. Said circulating electrolyte in passing through annularspace 38 cools anodes 36. The circulating electrolyte then flowsdownwardly through downcomer conduits 40 wherein the heat collected bythe electrolyte is dissipated through the walls of the downcomer tubesand removed from the system by means of coolant introduced throughcoolant inlet means 20 and removed via coolant outlet means 26. Ifdesired, said gas lift effect can be augmented by means of a suitableinert gas introduced into said annular space 38 by means of headerarrangement 68 connected to conduit 70 which in turn is connected to asuitable source of inert gas.

Said inert gas can be any gas which is inert, or essem tially inert,with respect to the electrolyte used in the cell, the feedstock, and theproducts produced in the cell. Examples of suitable inert gases includethe commonly known inert gases such as helium, argon, krypton, xenon,nitrogen, etc. Nitrogen, because of its ready availability, is onepreferred gas. Frequently, a gas produced in the electrochemicalconversion process can be employed as the inert gas. When such gasesproduced in the process are available, they represent a preferred gasfor use in the practice of the invention. For example, in theelectrochemical fluorination of fiuorinatable organic compounds using anelectrolyte comprising hydrogen fluoride, some perhalogenated compoundsare frequently produced in the process. Said perhalogenated compoundsare inert in the process and can be used in the practice of theinvention to enhance circulation of the electrolyte through said annularspace 38. Hydrogen is produced at the cathode in such fiuorinationprocesses and can be used to enhance said circulation.

The electrolytic cells of the invention are applicable to a wide varietyof electrochemical conversion processes. The cells of the invention areapplicable to any electrochemical conversion process wherein it isdesired to remove heat of reaction from the system. Said electrolyticcells can be employed in systems where heat is liberated at the anode orin systems where heat is liberated at the cathode. Where the principlereaction is occurring at the cathode and heat is liberated at thecathode, the above designated cathodic tubes are designated as anodictubes and contain a cathode. Thus, generically speaking, cathodic tubemeans 34 can be referred to as an electrode tube means, and anode means36 can be referred to as an electrode means. Some examples of processeswherein the cells of the invention can be employed are electrochemicalhalogenation such as the fiuorination process described above,electrochemical cyanation, and cathodic conversions such as thereduction of alcohol to hydrocarbons or the reduction of acids toalcohols.

Further details of an electrochemical fiuorination process in which thecells of the invention can be employed can be found in US. Pat.3,511,760, issued May 12, 1970, to H. M. Fox and F. N. Ruehlen. See alsoU.S. Pats. 3,461,049 and 3,461,050, issued Aug. 12, 1969, to W. V.Childs.

The electrolytic cells of the invention can be of any suitabledimensions, depending upon the process to be carried out therein, andthe desired throughput for said process. By way of example, and not byway of limitation, in one embodiment of the invention the heat exchangershell 14 was designed to have an overall length of approximately 90inches and overall width of approximately 75 inches, with cathodic tubes34 having an outside diameter of approximately 9 /2 inches, anddowncomer tubes 40 havng an outside diameter of approximately 6 /2inches. The overall height of said heat exchanger shell 14 wasapproximately 30 inches. Anode 36 had an overall length, includingfittings on the top, of approximately 36 inches. Said anode had anoverall outside diameter in the carbon portion of approximately 7 /2inches. The remainder of the elements of the cell were generallyproportional 1n slze.

While certain embodiments of the invention have been described forillustrative purposes, the invention is not limited thereto. Variousother modifications or embodiments of the invention will be apparent tothose skilled in the art in view of this disclosure. Such modificationsor embodiments are within the spirit and scope of the disclosure.

We claim:

1. An electrolytic cell comprising, in combination:

a container;

a heat exchanging shell mounted in said container and dividing saidcontainer into an upper electrolyte chamber and a lower electrolytechamber;

a coolant inlet means in communication with a passageway formed in saidheat exchanging shell as described hereinafter;

a coolant outlet means in communication with another passageway formedin said heat exchanging shell as described hereinafter;

at least one bafile means extending across said heat exchange shell froma wall thereof and between said inlet means and said outlet means so asto form a plurality of said passageways for multiple pass flow ofcoolant through said shell between said inlet means and said outletmeans;

a plurality of electrode tube means extending in a generally verticaldirection through said shell and said baffie means, and in communicationwith said upper and lower electrolyte chambers;

a plurality of downcomer tube means extending in a generally verticaldirection through said shell and said bafile means, and in communicationwith said upper and lower electrolyte chambers; and

a plurality of electrodes disposed in said electrode tube means withspace surrounding said electrodes so as to preserve said communication;and

wherein said electrode tube means and said downcomer tube means arearranged in alternate rows, with respect to each other, extending acrosssaid container and said shell.

2. An electrolytic cell in accordance with claim 1 wherein the centersof said downcomer tubes in a row thereof are positioned between thecenters of said electrode tubes in an adjacent row thereof.

3. An electrolytic cell in accordance with claim 1 wherein each one ofsaid downcomer tubes is disposed generally at the center of a cluster ofa plurality of said electrode tubes.

4. An electrolytic cell in accordance with claim 3 wherein said clusterof electrode tubes comprises four tubes arranged in a generallyrectangular pattern.

5. An electrolytic cell in accordance with claim 1 wherein:

said coolant inlet means and said coolant outlet means are bothconnected to the same wall of said shell and are positioned one abovethe other; and

a single baille means is connected to said same wall of said cell andextends therefrom between said inlet means and said outlet means.

6. An electrolytic cell in accordance with claim 1 wherein:

one of said coolant inlet means or said coolant outlet means ispositioned adjacent to and spaced apart from the bottom of said shell,and the other of said inlet means or said outlet means is positionedadjacent to and spaced apart from the top of said shell;

a plurality of said baflle means is provided;

a first one of said means is connected to said wall of said shell abovesaid one of said inlet means or said outlet means which is positionedadjacent the bottom of said shell; and

the last one of said baflle means is connected to said wall of saidshell below said other of said inlet means or said outlet means which ispositioned adjacent the top of said shell.

7. An electrolytic cell in accordance with claim 6 wherein said coolantinlet means and said coolant outlet means are both connected to the samewall of said shell and are positioned one above the other.

8. An electrolytic cell in accordance with claim 6 wherein said coolantinlet means and coolant outlet means are connected to opposite walls ofsaid shell.

9. An electrolytic cell in accordance with claim 8 wherein:

said container is generally rectangular in shape;

10 said heat exchanging shell conforms in shape to the wherein saidcontainer is generally circular in shape inshape of said container;stead of rectangular. said electrodes are individually suspended in saidelectrode tube means with an annular space surrounding References Citedsaid electrodes so as to preserve said communication; 5 UNITED STATESPATENTS and means are provided for connecting each of said elecg ;3$trodes to a source of electric current. l:492121 4/1924 Cruser et a1 10.An electrolytic cell in accordance with claim 9 wherein fins areprovided on the internal surfaces of said 10 JOHN M ACK, PrimaryExaminer downcomer tube means.

11. An electrolytic cell in accordance with claim 9 SOLOMON, AisistantEXamiIlBl' wherein said electrode tube means is a cathodic tube and saidelectrode is an anode.

12. An electrolytic cell in accordance with claim 11 15 204-262 274UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Non3,692,660 De d= September 19, 1972 R. B. Maclmllin et al p It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

' Column 1, lines 5 and 6, delete "(all c/o Phillips Petroleum Company,

Bartlesville, Okla. 71 ,003) and insert therefor aesignors .to PhillipsPetroleum Company, Bartlesville, Oklahoma 7h.00h column 8, line 1 ,7,delete "cell" and insert therefor shell v Signed and sealed this 3rd dayof April 1973.

(SEAL) Attest:

EDWARD M.FLETQHER,JR. I ROBERT GOTTSCHALK Attestlng Offlcer Commissionerof Patents

